Safety guard mechanism for power driven presses and other machines



May 5, 1936. 2,039,964 SAFETY GUARD-MECHANISM FOR POWER DRIVEN PRESSESAND OTHER MACHINES J. C. JUNKIN 5 Sheets-Sheeb 1 Wm. a

I c/bfi/i [ii/121 172 m w WW W Filed April 19, 1954 y 1936- J. c. JUNKIN7 2,039,964

SAFETY GUARD MECHANISM FOR POWER DRIVEN PRESSES AND OTHER MACHINES FiledApril 19, 1934 .5 Sheets-Sheet 2 5 Sheets-Sheet s May 5, 1936. J. c.JUNKIN SAFETY GUARD MECHANISM FOR POWER DRIVEN PRESSES AND OTHERMACHINES Filed April 19, 1934 eg m 5 Sheets-Sheet 4 E] YVU Mm J. c.JUNKIN SAFETY GUARD. MECHANISM FOR POWER DRIVEN PRESSES AND OTHERMACHINES Filed April 19, 1934 y 1936- J. c. JUNKIN 2,039,964 SAFETYGUARD MECHANISM FOR POWER DRIVEN PRESSES AND OTHER MACHINES Filed April19., 1954 5 Sheets-Sheeb 5 Patented May 5, 1936 UNITED STATES awashPATENT OFFIQE SAFETY GUARD MECHANISM FOR POWER DRIVEN PRESSES AND OTHERMACHINES Application April 19, 1934, Serial No. 721,406

19 Claims.

..In..an application for Letters Patent of the United States filed by meMay 23, 1932 and numbered, serially, 613,056, I have shown, describedand. claimed a safety guard mechanism for 5 punching, stamping andembossing presses, and other power driven machines such as shears, etc.,all of which, for the sake of brevity, are gener-ically, referred to asmachines. My said safety; guardv mechanism comprises a locking 1 meanshaving members co-operating with each other and with elements of themachine to which itis applied to prevent movement of the ram, plunger orcorresponding part (hereinafter called .fworking member) of said machineto its workng position in the event that movement of the guarding memberto its guarding position is obstructed, either by the hand of theoperator or otherwise. My said locking mechanism is characterized, amongother things, in that it includes 20 members :co-operating to cause thefollowing phases of movement of the guarding member, and the workingmember of the machine to which the guard is applied when pressure isapplied to the other operating lever (which is usually of a foot- 25operated nature though it may be and sometimes ,is manually operated) ofthe machine, namely, the pressure .(l) releases the guarding memberandpermits the latter to fall, by gravity, (2) at themoment saidguarding member begins to fall 30 the operating lever is locked againstmovement until the guarding member has reached its final guardingposition so that if the latter meets with an obstruction to its downwardprogress the operating. lever (shown as a pedal or treadle) remains inlocked position and any pressure imposed thereon is not transmitted tothe guarding member, orto any part of the machine whose operation by.the operating lever would permit move- .ment of :the working member;(3) when, and only when, .the guarding member has reached its finalguarding .position the operating lever is released and by its downwardmovement becomes operative upon the clutch-trip pawl or dog of themachine, to release the mechanism which transmits 45 reciprocatorymovement to the working member; (4) movement of the guarding membertoward its non-guarding position commences immediately before .theworking stroke of the work ing member, to thereby give free access tothe die "and work operated on during the return stroke of the. workingmember, but this return movement of the guarding member does notcommence until said working member has reached a position at .which theinterposition of the guarding member between the same, and the hand ofthe operator is no longer required; and (5) the operating lever will bereturned to its non-operating position and in its return movement willcause or permit the working member to be locked at the end of itsnon-working stroke until again released by repe- 5 tition of theforegoing phases of movement.

In the foregoing, and certain other respects, the instant invention issubordinate to certain claims of the aforesaid application for patent, aprincipal purpose of the present invention being to improve the lockingmechanism shown, described and claimed in said application in certainrespects by which its safety features will be extended to give absoluteassurance against any repetition of the movement of the working meml5ber of the machine to which it is applied unless and until the guardingmember is in its fully guarding position, whether such repetition isbrought about by accident, by Wear or by breakage or any other causewhich unless guarded against would release the working member for itsworking stroke at a time which would endanger the operator.

The invention of the instant application for patent comprises certainnovel arrangements and combinations of parts providing a mechanismapplicable in principle to an infinite variety of power driven machineshaving working members of a nature such as to call for the guarding ofthe operator against injury from said members, an important purpose ofthe invention being to so co-or-dinate the elements of the guardingmechanism that the machine will be positively and unfailingly lockedagainst working movement at all times except when the guard is in itsfully guarding relation to the working members of the machines,respectively.

The accompanying drawings illustrate, and I will hereinafter describe,this guarding mechanism as applied to a stamping or punching press inwhich the guarding member and the locking members are positioned to workin vertical or substantially vertical direction, but I recognize thefact that in some machines said guarding member and locking members, andappurtenant parts, should be arranged to work horizontally, and I wouldhave it understood, therefore, that the arrangement herein illustratedis exemplary only. Whatever changes are necessary to adapt the mechanismto work horizontally are within the purview of the skilled mechanic andhence need not be illustrated or described herein.

In said drawings, wherein like characters of reference denotecorresponding parts in the several views:-

, tened relation to the adjacent end of the mem- Fig. l is an elevationof a punch or stamping press viewed from one side and showing theguarding member, proper, in its non-guarding position in full lines andin its fully guarding position in dot-and-dash outline;

Fig. 2 is a vertical section showing the clutch mechanism, the line ofsection being indicated at 22 on Fig. 1;

Fig. 3 is an elevation of the machine viewed from the side opposite thatshown in Fig. 1 and shows the guarding member, proper in its fullyguarding position in full lines and in its nonguarding position indotted outline;

Fig. 4 is a detail View of the guard-timing means showing the positionof the elements thereof when the guard is in either its fully guardingor in its non-guarding position;

Fig. 5 is a detail representation showing the course of travel of theeccentric or crank p0rtion C of the crank shaft in the movement of theworking member of the press through its working stroke, the guardingmember remaining stationary during said travel due to lost motion in thetiming means;

Fig. 6 is a vertical section on the line 66 of Fig. 4, showing also thetiming means in its fasber C of the crank shaft, said member being shownas broken off;

Fig. 7 is a view of the timing means as seen from the side opposite thatshown in Fig. 4;

Figs. 8-12, inclusive, are detail views, with the face plate of thelock-casing removed to expose the locking and releasing members therein,and

shows said members in the various relative positions to which they aremoved in the operation of the press and guarding member, proper-Fig. 8showing the position of said members in the interims between successiveoperations of the press and when the guarding member is in itsnon-guarding position; Fig. 9 showing the position of said members whenthe operating lever, a pedal in this instance, has been depressedsufficiently to free the guarding member for its movement towardguarding position, Fig. 10 showing the relative positions of saidmembers when the guarding member has reached its fully guardingposition, Fig. 11 showing the position of said members when the clutchhas been released to thereby permit movement of the working member ofthe press to its working position and Fig. 12 showing the relativepositions of said members during the returning movement of the guardingmember to non-guarding position and in the position in which the pedalis detached from the clutch release means;

Fig. 13 is a detail perspective view of the latching member viewed fromthe under or rear side thereof; and

Fig. 14 is a transverse section on the line l4- 14 of Fig. 11.

The illustrated press is of usual construction for punching and/orstamping operations, including a ram A whose upper end is connected by apitman B with the eccentric or crank portion C of a crank shaft havingmembers C and C which extend laterally in opposite directions from saideccentric portion C and are journalled in suitable bearings in the framepart D of the press. The crank or eccentric portion of saidshaft,.together with the member C are shown in dotted outline in Fig. 3,as is also the pitman, and the member C of said shaft is shown in fulllines, but broken off, in Fig. 2, and in dotted outline in Fig. 1.

On the member C of the crank shaft is a braking means E, as usual, andsaid member C also carries a timing means, hereinafter particularlydescribed, whose function is to assure return movement of the guardingmember in a predetermined timed relation with respect to the movementsof the working member A, which as already stated, is carried by theeccentric portion C of the same crank shaft. Mounted on the other memberC of the crank shaft is a clutch mechanism which, as shown in Fig. 2,comprises a flywheel F with clutch jaws ,f, a collar F keyed orotherwise fastened against movement on the member C a dog or pawl Fhaving a spring I tending to move it into locking engagement with theclutch jaws f and a clutch release cam F arranged to control movement ofthe dog or pawl into and out of engagement with the clutch jaws andbeing itself under control of the operating lever G and lockingmechanism hereinafter referred to. The cam F is providedwith acompression spring I which acts to force it'- yieldably to its clutchreleasing position. The bearings for this member of the crank shaft aremarked 0 It will be understood that, with the exception of the timingmeans whose function has been briefly set forth and which timing meanswill be hereinafter described in detail, the mechanism thus fardescribed is substantially embodied commonly in presses for punchingand/or stamping and/or embossing purposes, respectively, and also inmachines for shearing, and in drop hammers and in other machines havingmeans for effecting intermittent motion of the work performing member.

G designates the operating lever of the machine, here shown as a pedalor treadle, having a spring g for returning it to its initial position,defined by a stop 9, when relieved of the pressure which operated it, asusual in this class of machines. H designates the guarding member,proper.

The operating lever G has connection with the clutch release cam F andwith the guarding member H, through mechanism including certainrelatively movable interlocking and releasing members hereinafterdescribed. These members are member is shown at I in Fig. 1. This casingmay be arranged in any suitable position with relation to the operatinglever and the parts actuated or controlled by said mechanism ineffecting the phases of movement of the guarding member and workingmember hereinbefore referred to. In the particular press illustrated forexemplary purposes in the accompanying drawings, the casing and itscontained interlocking and releasing members are mounted above one endof the. guarding member H, this being a convenient location therefor inthis particular press.

The illustrated guarding member H is of substantially the sameconstruction as that illustrated and described in my co-pendingapplication (Se-r. No. 613,056) hereinbefore referred to. It is shown ina position whereby it may be moved gravitationally toward its guardingposition and receives movement in the opposite direction from atransversely extending shaft J with which its side members haveconnection in any suitable way, either directly or indirectly accordingto the requirement of the particular machine to which the guardingmechanism is applied. It is here shown as having its opposite side arms,at points opposite its guarding end,

mounted in a casing, whose face fixed directly to the shaft, this beingan appropriate means of connection in the particular machine illustratedin this application for exemplary purposes.

Reference has heretofore been made to a timing means operatively relatedto the guarding member. This timing means includes two complementarymembers, to wit, a loose disk K and a stop plate K relatively to whichthe loose disk is rotatively mounted, the stop plate beingfixedlysecured to the contiguous end of the member C ofthe crank shaft,by bolts k or other appropriate fastening elements, and having a pinwhich projects laterally from its surface opposite the member C and uponwhich the loose disk is rotatably mounted. The loose disk K is providedwith a pin k which projects laterally from opposite surfaces of the diskand the stop plate is provided with a cutaway portion k which forms achannel into which one end of said pin 70 projects. X designates acasing which is arranged between the stop plate K and the member C ofthe crank shaftand has a-circumferential flange which extends over theperipheral portions of said stop plate K and loose disk K and providesfor the retention of grease or other appropriate lubricantwhich may besupplied to the channel 10 in any appropriate way.

'Upon the end of the pin 10 opposite the stop plate there is journaledthe upper portion of a bearing L whose lower portion is hollowand-receives a rotatable member L which extends across the said lowerportion-of the bearing at substantially right angles to the pin 10 "Thismember L is formed with an opening into which projects the upper end ofa lifting rod L which is fixed in a set position therein by a fasteningbolt Z whose head is exposed at the side of the bearing and whose innerend impinges upon the side of the lifting rod.

The mouth leading to the interior of said bearing and through which thelifting rod L extends into the member L is flared and said bearingprovides a connector which, through its member L permits the lifting rodL to have back and forth swinging movement about the axis represented bythe pin 76. This connector also enables said rod to be set into properposition with relation to the shaft J and also to the guarding member Hto which its lower end is connected through the medium of a connector M.This connector M is carried by and has pivotal -movement relatively to,the corresponding side arm of the guarding member, the pivot of saidconnector being indicatedat m in Fig. 3.

The lower end of said lifting rod extends loosely through and protrudesfrom, the connector M and it is provided below the latter with anadjustable stop m which impinges against the connector M and enables therod to lift the guarding member to non-guarding position. The cutawayportion of the stop plate K hereinbe-fore referred to is formed at itsopposite ends to provide stops respectively marked a and b, to engagethe pin k These stops are preferably concave in-order that the pin itwill be effectively seated therein at the ends of the travel of theloose disk K relatively to the stop plate K Mention is here made of thefacts that this travel of the loose disk is about the pin k and occursin the present instance by gravity under the weight of the lifting rod Land bearing member L when the guard reaches its non-guarding positionand that in said movement the-liftrecess 2.

ing rod passes loosely through the connector M so that the stop m isthereby spaced from the connector to permit the'guard to fall intoguarding position-relatively to the rod at a predetermined time-in themovement of the operating lever G of the machine, all as will behereinafter more fully explained.

Therelatively movable interlocking and releasing members hereinbeforereferred to as beingmounted in a casing whose face member is shown at Iin Fig. 1, are shown in Figs. 8-12, inclusive in various positions theyoccupy relatively to each other in operation. In these figures themembers are shown in operative relation with a backing member I which inconjunction with said face member I forms a casing which receives saidmembers and prevents interference therewith. Their ends protrude fromsaid casing for connection, respectively, to the guarding member and theparts of the machine whose operations are controlled thereby when theoperating lever is set in motion.

As here shown and as preferred the said locking and releasing mechanismincludes three relatively slidable members respectively marked N, O andP, a latching member Q and a backing member R. The-members N, O and Phave endwise relative sliding movement in the casing and the members Qand Ralso have endwise sliding movement in the casing but are arrangedsubstantially at right angles with the members N, O and P. In additionto the foregoing members, this locking and releasing mechanism includesa floating lever S to which is pivoted, at s, the corresponding end of amember S One end of the member N has engagement throughout certainportions of its length with the corresponding edge of the member 0 andthe other edge of said member 0 has engagement with the correspondingedge of the member P, for guidance purposes, the casing also being soformed that it will have a guiding function with relation to saidmembers N, O and P and also with relation to the latch Q and backingmember R, as in my application, serially numbered 613,056, hereinbeforereferred to.

The latching member Q and the backing member R are respectively providedwith springs Q and R and said backing member also has afriction-reducing roller R to engage the corresponding edge of themember N. The spring Q is arranged to press the latching member Qyieldably into operative relation with the members N and P and thespring R is arranged to hold the-roller R yieldably against thecorresponding edge of the member N. It will be noticed that the backingmember R extends partway over the face of the member Nand toward the endof said latching member.

The inner longitudinal side of the member N is provided near its upperend with a recess I and immediately below said recess with a deeperrecess 2. These recesses are defined by a beveled shoulder 3 and asquare shoulder 3 at opposite ends of the recess I and by said squareshoulder 3 and a square shoulder 3 at opposite ends of the Said innerlongitudinal side is also formed with a recess l arranged betweenshoulders 4 and 4 The inner longitudinal surfaces 5, 6 and l of thismember (N) are in longitudinal alinement with each other and thesurfaces 1 and F 8, which form inner walls of the recesses I and 4,respectivelyare substantially in alinement one with the other while thesurface 9, which forms the inner wall of the recess 2, is arrangedrearward of the lines of the walls I and 8. The outer wall or edge In,except for the indentation II, is plane throughout. This member (N) isalso provided, near one of its ends with a stop I2 which projectslaterally therefrom in opposite directions from its front and rearsides. Thus it is similar in all substantial respects to thecorresponding member shown in my aforesaid application for patent,except that the recess 8 does not extend to the lower end of the memberand has its opposite ends defined by shoulders l and 4 When operativelyrelated to the machine it is connected to the guarding member H throughthe medium of an appropriate rod T one end of which is connected by asuitable connector T to the member N at the opening l3 when the lockingand releasing mechanism is arranged above said guarding member, and atthe opening l3 when it is arranged below said guarding member. Theopposite end of said rod T is connected to the guarding member H by anappropriate connector T The member is of different construction incertain respects and has a different function from the correspondingmember shown in my aforesaid application. It is provided along one sideand intermediate its ends with a recess 14, one end of which is definedby a square shoulder l5 and the opposite end of which is defined by abeveled shoulder l6 which acts as a cam to free the floating lever Sfrom the member P as hereinafter more fully explained. It is alsoprovided at one end with a foot piece H which is suitably fixed theretoand, in practice, may be integral therewith. This foot piece projectslaterally beyond the opposite sides of the member 0 and provides aflange one edge of which is received within the recess 4 in the member Nand the opposite edge of which is received within a recess 18 which isformed in the contiguous longitudinal edge of the member P and isdefined at one end by a shoulder H).

The other edge of the member P is formed, about midway of its length,with a recess 20 so formed as to provide a plane shoulder 2? at one ofits ends a rearwardly beveled wall 22 which extends from said shoulder2| to the inner wall 23 of the recess, and a plane shoulder 24 at theend of the recess opposite the shoulder 2| and inwardly offset from thelatter shoulder. As thus far described this edge of the member issimilar to the corresponding edge of the corresponding member shown inmy aforesaid application for patent, but the shoulder 24 in this memberP is comparatively short. Said edge is formed with an additionalshoulder 25 which is space-d from the shoulder 24 and is shown as beingoiTset therefrom. These shoulders 24 and 25 are connected by a wall26-and the shoulder 25 is slightly concave to form a depression at itsjunction with said wall and the edge 28 extending from said shoulder 25to the corresponding end of the member abuts against one edge of aguiding element 29 which forms a part of the backing member I Theopposite edge of said guiding element is rounded as shown at 30 in orderthat it will not interfere with movements of the members S in theoperations of the floating lever S and operating lever G.

The latching member Q, shown in detail in Fig. 13, is of the sameconstruction as the corresponding member in my previous applicationhereinbefore referred to. Its undersurface is formed with a transverseopening Q and has a plane wall q which defines one end of the openingand the other end of said opening is defined in part by a plane shoulderq and by a beveled shoulder q The member P extends through the opening Qin the latching member and said opening enables the latching member tohave horizontal endwise slidable movement relatively to the member P andthe member P to have endwise vertical slidable movement relatively tosaid latching member. The beveled portion q of the latching member isarrange-d to be contacted by the beveled wall 22 of said member P and inthe sliding movements of the latter member to cause said latching memberto be retracted automatically in the downward movement of the member P.The upper surface of the latching member, adjacent the beveled portion qprovides a stop q to co-operate with the shoulder 25 in preventingdownward movement of the member P beyond the position shown in Fig. 9when downward movement of the guarding member H to its fully guardingposition is obstructed.

The member P when operatively related to the machine is connected to theclutch releasing cam F through the medium of a rod U one end of which ispivoted to said cam at d and the other end of which has a lost motionconnection with the member P through the medium of a connector U havinga pivot pin 32 loosely mounted in an opening 3| in the member P.

This connector U and also the connectors T and '1 intermediate themember N and the guarding member H, are each preferably of the sameconstruction as the connector illustrated and described in my aforesaidapplication for Letters Patent, to which reference may be made for a.full understanding thereof. The nature of each of these connectors issuch that quick and accurate adjustment, as well as pivotal movement ofthe rod U or the rod T, as the case may be, relatively to the member Por the member N and guarding member H is permitted without puttingstrain on the pivotal connection.

The floating lever S is pivoted at s to one end of a member S whoseopposite end is connected to the operating lever G (as the treadle orpedal here shown), the connection including a rod V which is preferablymade in sections having overlapping ends held in fixed relation witheach other by an appropriate means 1) in order that the rod V may beadjusted in accord with the position of the frame part D which, as iscommon in this class of machines, is adjustable pivotally to variousangles relatively to the base D of the press about the axis at d and isfixed in adjusted position by means indicated at d. Interposed in theconnection between the operating lever G and member S is a spring 33 anda frame for said spring, the frame having side members 34 and a bottommember 34, the latter being provided With an opening through which thecorresponding end of the rod V extends and the side members 34 havingpivotal connection to the member S at 35. The upper end of the rod Vextends through this spring and is arranged between the side members 34and has its end provided above said spring with nuts 36 which areadjustably fixed thereon and form abutments for the corresponding end ofthe spring, the other abutment for said spring being provided by thebottom member 34 of the spring-frame. This spring permits the operatinglever to be pressed to its extreme movement in one direction (toward thefioor in this instance) without putting overstrain on the lockingmechanism when the movement of N the guarding member H to its fullyguarding position is obstructed. The rod V is provided below the bottommember 34' of the spring-frame with a flange 3'! through which movementis transmitted to the floating lever, through the spring frame andnember S under control of the pedal spr 9- The endwise movable member isarranged between and with portions of its side edges in contact with,the corresponding edges of the members N and P and, moreover, is sopositioned that its outer face is rearward of the plane of the ,outerfaces of said. members N and P, as shown in. Fig. 14.

10 Thecorrelation of the members N, O, P and Q Wissuch that theymutually have a guiding function with respect one to another, and theface and ,backing members I and I of the casing are suit- .ably formedwith relation to said members to ,assure'that there will be no wobblingtendency which would interfere with their accurate operation. In theserespects, the present construction is similar to the construction shownand described in my previous application hereinbefore re- 'ferred to.

The inner end portion of the floating lever S is forked .to provide achannel through which the -en'dwise movable member'P extends and the opvposing walls' (31 and 31) of said channel are so arranged that theyguide said member in the travel of the latter between the same. Theforked end of said-floating lever is provided with a pin :38 which isnormally seated in the depression 25 inthe member P and the freeextremity of the inner wall 31 of said forked end portion is beveled, asshown at 39, and is so arranged that it will ;be contacted by thebeveled shoulder IS on the mem- ;ber O in the upward movement of thelatter member and will receivepressurefrom said beveled .35 shoulderacting to move thepin 38 out of the depression25 and to force thefloating lever away from the member O and out of engagement with themember P. The member P is thus freed and permitted to be raised intolocked position with ,40 respect to the latching member Q. 40 designatesa spring which is arranged'within the lever and has one of its endsbearing'against the inner end of a plunger-4| whose outer end engages-awall or member 42 of the casing, which wall or member 45 acts as astopto cause said spring to be placed undertension in the endwise outwardmovement of the lever. '-It will be apparent that when the pin 38 hasbeen disengaged" from the depression 25 it will be pressed by the springagainst the edge *Of the member P in the movement of the latter toitslocking position relatively to the latching member Q and that in thereverse movement of tsaidmember P the spring will cause the pin to 1snap into said depression.

The'free edge of the wa1l3'l of the forked end rportion of. the.floating .lever S is shown as being :beveled similarly to thecorresponding part of the W3}11.31, but this is merely forconvenience inmanufacturing the lever, it being evident that this :free edge of thewall 31' has no function in forc- :.ing the leverirearward when thecorresponding surfaces of members N,;O andRhave the relationshiphereinbefore-set forth: it being the free extremity of the wall 31Whichacts in this respect by contact therewith of the beveled shoulderI6. --When5the machineis idle, as in the interim between successive workperforming operations, the parts of the locking mechanism are in therelative positions shown in Fig. 8 and the guarding member, ram, latchreleasing cam, etc. are

jin the positions shown in Fig. 1 and the timing :means is in theposition shown in Fig. 4 with a ,liftin rod in the position shown inFig. 3. In

3; the guarding member isshown in nonguarding; position in dot-,and-dashoutline and it from the shoulder 3 .5 floating lever S and pin 38.

should be noted that the connector M is in the raised position andspaced-from the stop m on the lifting rod, the lifting rod being in-theposition shown in dotted outline inFig. 3.

Upon reference to Fig. 8, it will be noticed that the latching end ofthe latching member Q ex- -tends into the opening 2in member N and hasits upper surface in engagement with the shoulder 3 and thereby servesto hold said member N against movement in a downward direction. Thelower surface of said latching member is spaced The foot piece I! ofthememberO rests upon the shoulder 4 near the lower end of member N and itsbeveled shoulder 13 is near but out of contact with the beveledsurface'39 of the floating lever. The shoulder 15 of this member 0 isabove and spaced from the upper surface of the latching memberand theshoulder-2l of the member P is also above and spaced from the uppersurface of said latching member. "The beveled wall-22 ofthis' member isin contact withthe bevelled portion 11 of the latching member and thelower surface of said latching member is spaced considerably from theshoulder'24. The pin 38 of the floating lever is within'the concave 25of leverP. Asshow-n in dotted outline in'Fig. 8 the pin 32 forming apivotal element of the connector U by which the rod U is connected tothe upper end of the member P isarranged in the lowerend of theelongated opening 3|.

With the parts in this position theoperation is asfollows: When pressureis-applied to the outer end of the operating lever G downward movementis transmitted to the member 1? through the rod V, spring 33, springcasing 34, member As the result of this downward movement of the memberP the beveled wall 22 thereof 'acts upon the beveled portion (1 of thelatching member Q to retract the latching end of the latter from theopening 2 in the member N, thereby freeing said member N and permittingthe guarding member H to'drop by gravity. The member 0 also drops bygravity with said guarding member, since its foot I! is now'freedfromthe shoulder 4 by which it was supported.

The elements are now in the position shown in Fig. 9, attention beingcalled to the fact that the shoulder 21- is now in contact with theupper surface of the latching member Q. It will be understood that thismovement was not transmitted to the rod U because of the lost motionconnection between said rod and the member P. I-Ience the clutch releasemechanism has not been affected and the working member A of the press isstill held against movement toward working position.

If the movement of the guard to its fully guarding position isobstructed the elements will-remain in the position shown in Fig.- 9. Inthis position the member P is locked against further down- Ward movementby reason of the-engagement of shoulder2l with the upper-edge 0f thelatching member, the working member A of the press hence remaininglocked against movement to its wgrking position. If, on the other hand,there is no obstruction to the movement of the guard- .ing member to itsfully guarding position the member N will continue to move downward andits shoulder 3 will act upon the corresponding edge of the latchingmember Q to force the latter to further retracted position, shown inFig. 10, thereby freeing the upper edge of said latching member from theshoulder 2| and permitting to the position shown-in Fig. 11. By thismovement of the member P the rod U is moved downward thereby acting uponthe clutch release cam F which by its action upon the dog or pawl Foperatesto engage the clutch, thereby permitting movement of the workingmember. It will be c1ear,however, that this movement of the workingmember does not commence until and unless the guard is in its fullyguarding position.

The parts are now in the position shown in Fig. 11, with the guardingmember H in the position shown in Fig. 3. This condition continues untilthe working member has almost completed its working stroke, at whichtime the guarding member commences its return movement to itsnon-guarding position, the beginning of this return movement beingaccurately timed with respect to the movement of the working member ofthe press, through the timing means hereinbefore referred to, saidtiming means operating as follows:

During the working stroke of the working member A the stop plate K isrotated by its connection to the member C of the crank shaft and itsstop member 22 is thereby brought into contact with the correspondingend of the pin k which in turn rotates the loose disk K, thereby raisingthe lifting rod until its stop m comes into contact with the connector Mon the guarding member and by its further upward movement raising theguarding member to the non-guarding position. When the guarding memberhas reached its non-guarding position the loose disk is permitted torotate by gravity, under the weight of the bearing L and rod L and saidrod L is dropped relatively to the guarding member H to the positionshown in Fig. 3. Through the described movement of the timing means withrelation to the guard, the shaft J is rotated, thereby communicatingreturn motion to the ;member N, through the rod T. In its returnmovement to its initial position the rod N acts on the foot I! of member0 and raises said member and said foot acts to raise the member P in atimed relation determined by the spacing of the upper edge of said footfrom the shoulder I9 of said member P. Return movement of member O toits initial position causes it also to move the floating lever outwardlyby the engagement of its beveled shoulder I6 with the beveled end 39 ofsaid lever, thereby disengaging the pin 38 from the member P, thisposition of the parts being shown in Fig. 2. I

This disengagement of the pin 38 fromthe member P occurs shortly afterthe foot I! has come into engagement with the shoulder i 9, the delayedmovement of member P with reference to members N and 0 beingnecessitated by the relative lengths of travel of the members N, O andP.

Member P being now disengaged from the floating lever S, the pedal isreleased from its operating connection with the operating mechanism ofthe machine. The pedal remains in this uncoupled Condition, in which itis inoperative with relation to the machine, until foot pressure hasbeen removed from the pedal and the latter has again been returned toits coupled position by the spring g. However, it will be seen thatunless the guarding member has returned to its fully guarding positionthe press cannot again be put in motion and, in short, cannot repeat itsoperation accidentally.

and the member P is thereby restrained from movement beyond that shownin Fig. 9, downward movement of the pedal G under pressure of the footof the operator may be continued without transmitting movement to themember P,

the compressive action of .the spring absorbing this further movement ofthe pedal. 7

At the end of the initial movement of the member P, as a result of whichthe guarding member H dropped toward its guarding position, the clutchrelease cam F is moved to thereby release thedog or pawl F which beingthus freed is moved into locking engagement with the clutch jaws F byits spring F, as previously explained. If the movement of the guardingmember to its fully guarding position is unobstructed the working memberA may now commence its working stroke. 7 At this time, and until theworking member has nearly completed its working stroke, the guardingmember is stationary. During this 'referred to part of the workingstroke of the work: ing member the timing member K is rotating while themember K remains stationary. This condition obtains until, by reason ofthe relative movement of said members K and K, the stop a at the end ofthe channel k in member K is brought into contact with the pin k carriedby member K. Further rotation of the crank shaft causes members K and Kto rotate unitar-. V ily, thereby communicating return movement of 1 theguarding member to its guarding position. In the initial part of thismovement, the portion of the timing means engaged with the rod L ispassing around the lower center of its course of travel and hence, slowreturn movement is transmitted to the guarding member. Further along inthe stroke the movement of the guarding member is accelerated since themovement communicated to the pin k is now in an upward direction. Thisaccelerated movement of the rod L transmits like accelerated movement tothe guarding member and begins at approximately the beginning of thereturn movement of the working member'A to its initial position;

As previously explained, the guarding member in its return movementtransmits corresponding movement to the member N of the lockingmechanism through the shaft J and, through the intermediate member 0,the member P is raised, thereby acting upon. the clutch release cam Fand holding it in a position in which it becomes effective upon the'pawlor dog F to thereby release the members of the clutch from theirinterlocked engagement with each other when the working member hascompleted its return stroke. It will be understood that when the membersN and P have thus been raised they are automatically locked in theirsaid position, through the action of the latching member Q and beingthus locked the clutch release cam F is also looked against anymovement, arising from any cause whatsoever, which would render itinefiective in stopping movement of the press at the moment the workingmember A has completed its non-working stroke and thereby brought thepawl or release dog F into engagement with the clutch release cam andcause the latter to release said pawl or dog from the jaws 1. V p

The, clutch members are held in their disengaged relation with eachother by the clutch release cam until the latter has been intentionallymoved by pressure applied to the operating lever G and until saidpressure is'efiective with respect to the rodV, member P and rod' U. Inthis connection, it will be remembered that pressure applied to theoperating lever is ineffective upon the clutch release cam unless anduntil the guarding member is in its fully guarding position. It willalso be remembered that at an early stage in the return movement of saidguarding member to its non-guarding position the operating lever Wasdisconnected from the mem- -ber P and that pressure applied to it fromany cause is not transmitted to said member P until '-after the clutchrelease cam has been moved v with the member P when the latter hasreached operated reciprocatory working member, .operating lever andcontrol connections between the operating lever and the working member:the said safety guard mechanism comprising a its elevated position. Thisreconnection of the operating lever with the member P hence does nottake place until the clutch release cam has been moved to and locked inits clutch releasing position thereby preventing more than one completereciprocation of the working member for each depression of the operatinglever. In other words, the correlation of the operating lever,

guarding member, clutch release cam and the connections between saidlever and cam is such that the working member must have completed itsnon-working stroke and the clutch release cam must have released theclutch dog or pawl from the clutch jaws before any pressure applied tothe lever will be again effective upon said clutch release cam, so thatunintentional repeating of the working stroke of the working member ispositively prevented under all conditions.

Having thus described the invention what I believe to be new and desireto secure by Letters Patent and what I therefore claim, is:

l. A safety guard mechanism applicable to a powerdriven machine havingan intermittently movable guarding member and means connected .to said.guarding member and arranged to be included in the control connectionsbetween the operating lever and working member, said means including adetachable member adapted for connection to the operating lever andoperative under control of the guarding member to disconnect saidoperating lever from the control connections during the return movementof the guarding member to its nonguarding position.

2. A safety guard mechanism applicable to a power driven machine havingan intermittently operated reciprocatory working member, an peratinglever and control connections between the operating lever and theworking member: the said safety guard mechanism comprising a movableguarding member and means adapted to be,controlled by the operatinglever for holding the guarding member releasably in its non- .guardingposition and the working member releasably in its non-Working position,said means including a series of members having relative movement one tothe other, one of said members ating lever and said working member andstill another being adapted for connection to the operating lever, saidmeans also including a member which forms a detachable connectionbetween the second mentioned and last mentioned members and is operativeunder control of the guarding member to release the operating lever fromthe control connections during the return movement of the guardingmember to non-guarding position, when the safety guard mechanism isapplied to the machine.

3. A safety guard mechanism applicable to a power driven machine havingan intermittently operative reciprocatory working member, an operatinglever and control connections between the" operating lever and theworking member: the said safety guard mechanism comprising a movableguarding member and means adapted to be controlled by the operatinglever for holding the guarding member releasably in its non-guardingposition and the working member releasably in its non-working position,said means including a plurality of relatively movable members having aninterlocking relationship one with another, one of said members beingadapted for connection to the guarding member and another being adaptedto form an element of the control connection between the operating leverand said working member, and also including a member adapted forconnection to the operating lever of the machine anda detachableconnection between the last mentioned member and the member secondmentioned, operative under control of the guarding member to release theoperating lever from the control connections during the return movementof the guarding member to its non-guarding position, when the safetyguard mechanism is applied to the machine.

4. A safety guard mechanism according} to claim 2, in which the memberwhich forms a tachable connection between the second mentioned and lastmentioned members is pivoted to the upper end of said last mentionedmember and is spring-pressed toward said second mentioned member and isprovided with a projection,@

mentioned members is pivoted to the upper end? of said last mentionedmember and is springpressed toward said second mentioned member and isprovided with a projection, and with a beveled free end to be slidablyengaged by the beveled wall of said additional member, and said secondmentioned member has an open-sided recess to receive said projection andfrom which the projection is raised and the member forced outwardly bythe beveled wall of the additional memher.

6. A safety guard mechanism for a power driven machine having anintermittently operated reciprocatory working member, an operating leverand control connections between the operating lever and the workingmember; said mechanism comprising a movable guarding member, a firstmember, having connection with the guarding member, a second member,detachable means to connect the second member with the operating lever,

said second member and detachable connection Operable upon initialmovement of the second member to release the first member to therebypermit the guarding member to move toward its guarding position and tolock the second member against further movement it movement of theguarding member to its guarding position is obstructed, means forreturning the guarding memher to its non-guarding position and meansoperable upon said detachable means to cause the lat er to bedisconnected from the second member while the guarding member isreturning to its nonguarding position.

'I. In a power operated machine having a movable working member, drivingmeans, an operating lever and control connections for effectingintermittent operation of said working member by said driving means: asafety guard mechanism comprising a guarding member mounted to havemovement to and from guarding position with respect to said-workingmember and means, including relatively movable members operativelyrelated to said control connections, and to the operating lever andguarding means, and operative to successively release the guardingmember for movement toward guarding position, lock said control meansagainst operative movement if movement of the guarding member to'itscompletely guarding position is obstructed and permit the guardingmember to continue its movement to its fully guarding position if thereis no obstruction to said movement, said means including a detachablymounted member having connection with the operating lever, andmeans fordetaching said member to thereby disconnect the operating lever, in thereturn movement of the guarding member to itsnon-guarding position,

' thefmachine also having means for effecting said return of theguarding member.

8. A power operated machine according to claim '7, in which the controlconnections include a clutch release cam which is positively held inlocked position when the operating lever is disconnected or when theguarding member is in unguarding position, whereby unintentionalrepeating of the movement of the working member is positively prevented.

9. In a power operated machine having a movable working member, drivingmeans, an operating lever and control connections for effectingintermittent operation of said working member from said driving means,said control connections having provision for lost motion and includinga first member and a. second member, the second member being connectedto the operating lever and provided with means forming a detachableconnection between it and the first member, a guarding member mounted tohave movement to and from guarding position with respect to said workingmember, a member having connection with the guarding member andoperative under control of the first member to release the guardingmember for movement to its guarding position 'in the initial part of themovement of said first 10. In a power driven machine, the combination ofa driving shaft, a working member, clutch members interposed between thedriving shaft and working member, a clutch release member,

a guarding member, an operating lever and control connections betweensaid operating lever and clutch releasing member and guarding member,and also between the guarding member and the driving shaft: saidconnections including elementary parts which cooperate, upon applicationof pressure to the operating lever, to permit the guarding member tomove to its guarding position and to move the clutch releasing memberinto clutch releasing position and cause the working member to beclutched to the driving shaft, said guarding member being arranged torelease its fully guarding position before the working stroke of theworking member commences, and the return connection to said guardingmember operating to return the latter to its non-guarding positionbefore the return stroke of the working member is completed, theconnections be-' tween the guarding member and the operating leveroperating to cause the operating lever to be operatively disconnectedfrom the clutch releasing member and'the latter to be, moved to and;locked in clutch releasing position before the operating lever is againoperatively connected to said clutch releasing member.

11. A power driven machine according to claim in which the returnconnections between the guarding member and the driving shaft arearranged'to cause return movement of the guard.- ing member to beinitiated before the working member has fully completed its workingstroke;

and is initially slow and-then more rapid to its fully non-guardingposition.

12. A power driven machine according to claim 10 in which the'connectionbetween the operating lever and the clutch releasing member includestently operated reciprocatory working member, a' guarding 'membermovable gravitationally into guarding position with respect to saidworking member, and'means, including a member having movement relativelyto the guarding member in one direction and operatively connectible tosaid guarding member for moving the same in the other direction, both ina timed relation with respect to the movements of the reciprocatoryworking member.

14. In a power driven machine, a shaft having an eccentric portion and abearing portion, a reciprocatory working member carried by the eccentricportion of said shaft, a guarding member and means for controllingmovement of the guarding member into and out of guarding position withrespect to the working member, including a member operative to move theguarding member in one direction and a lost motion connection betweensaid guarding member and the bearing portion of the shaft, arranged topermit the guarding member to move gravitationally to its guardingposition in advance of the working stroke of the working member and tocommence its movement to its non-guarding position in advance of thereturn movement of the working member to its initial position.

15. In a power driven machine, an intermittently operated reciprocatoryworking member, a

guarding member movable into and out of guard ing position with respectto said working member, a member for moving the guarding member in onedirection and a lost motion connection between the guard moving memberand the working member, arranged to permit the guarding member to movegravitationally to its guarding position in advance of the Workingstroke of the working member and to commence its movement to itsnon-guarding position in advance of the return movement of the workingmember to its initial position.

16. In a power driven machine, an intermittently operated reciprocatoryworking member and power shaft for the same, a movable guarding member,and means for automatically controlling movement of the guarding memberinto and out of guarding position at predetermined times with respect tothe movements of the working member, said means comprising a pair ofcomplementary members automatically connectible to each other forunitary movement and disconnectible from each other for relativemovement, one of said members being mounted to have movement throughoutmovement with and of the power shaft of the working member and the otherhaving connection with the guarding member.

17. In a power driven machine, an intermittently operated reciprocatoryworking member and power shaft for the same, a movable guarding member,and means for automatically controlling movement of the guarding memberinto and out of guarding position at predetermined times with respect tothe movements of the working member, said means comprising a pair ofcomplementary rotatable members, one of which is formed with a channeland is movable with and throughout movement of the power shaft of theworking member and the other of which is provided with a projectionwhich extends into said channel, said channel and projection 00- actingto permit relative movement of the members throughout a part of acomplete rotation of one of the same and to cause unitary movementthereof throughout the remaining part of said rotation.

18. In a power driven machine, a shaft having an eccentric portion and abearing portion, a reciprocatory working member carried by the eccentricportion of said shaft, a guarding member and means for controllingmovement of the guarding member into and out of guarding position withrespect to the work performing member, including a member having aslidable connection with the guarding member in one direction ofmovement of the latter and operatively connectible to said guardingmember for moving the same in the other direction, and a lost motionconnection between said guard-moving member and shaft, comprising acomplementary pair of members automatically connectible from each otherfor relative movement, one of said members being connected to thebearing portion of the shaft and the other having connection with theguard-moving member.

19, In a power driven machine, a shaft havingv an eccentric portion anda bearing portion, a reciprocatory working member carried by theeccentric portion of said shaft, a guarding member and means forcontrolling movement of the guarding member into and out of guardingposition with respect to the work performing member, including aguard-moving member having a slidable connection with the guardingmember in one direction of movement of the latter and operativelyconnectible to said guarding member for moving the same in the otherdirection, and a lost motion connection between said guard-moving memberand the bearing portion of the shaft, comprising a complementary pair ofrotatable members one of which is attached to the bearing portion of theshaft and has a channel which extends partway around the same and theother of which is provided with a projection which extends into saidchannel and has connection with the corresponding end of theguard-moving member, one end of said channel forming a stop which isengageable by said projection at the end of relative rotary movements ofthe members and said stop and projection being relatively arranged topermit relative rotation of the members and to cause unitary rotationthereof, during successive periods in the reciprocatory movements of thework performing member.

JOHN C. JUNKIN.

